The invention relates to a method for using a thread cutter in order to create an inner thread in an essentially cylindrical opening of a body having a center axis, whereby the cylindrical opening has at least one groove that runs essentially in the longitudinal direction, whose depth is equal to or greater than the outer radius of the thread cutter as measured from the center axis, whereby a projection that extends radially inwards and axially is provided in the body after the groove as seen in the circumferential direction. Moreover, the invention relates to a combination of a thread cutter and a body having a cylindrical opening with at least one groove that runs essentially in the longitudinal direction.
Various production methods are known for purposes of creating an inner thread in the opening of a body, for example, a concrete anchor. Normally, such threads are made using a thread cutter that is screwed into the opening and that cuts the thread during the screwing procedure. In this process, the thread cutter can only cut one thread track for each rotation of the thread cutter, in other words, a thread section that encircles 360°. Consequently, many rotations of the thread cutter are needed in order to create a long thread. By the same token, after the thread has been completed, such a thread-cutting tool then has to be unscrewed from the entire length of the thread.
In order to accelerate this procedure, European patent application EP 2 218 536 A1 discloses a thread cutter that has several radially projecting cutting edges arranged one after the other in the axial direction, whereby the number of cutting edges matches the desired number of thread tracks. The workpiece that is to be processed has an opening with at least one groove that runs in the longitudinal direction and that corresponds to the cutting edges. The thread cutter can be pushed into the opening, during which process the cutting edges of the thread cutter are inserted into the groove.
In order to cut the thread, the thread cutter is subsequently rotated around its longitudinal axis. In this process, starting at the groove, each cutting edge cuts a complete thread track until the cutting edges end up in the groove once again after a rotation by 360°. Subsequently, the thread cutter can be pulled back out of the opening in the axial direction. Therefore, the entire length of the thread is cut with a single rotation of the thread cutter. This makes it possible to create a thread much more quickly. A problematic aspect of this production technique is that it requires a great deal of force in order to cut the thread.